Thanks a lot, that's really great I am at work at the moment but as soon as I get home I will be following your advice....
Basically I need to 'clean up' the faces/edges/vertices that I'm not using before I go onto the next part right?

One thing that may? have caused the problems... I'm not sure if I am doing it correctly? Probably easiest to explain how I made the walls and you tell me if it's wrong...

1./ OK I Selected a poly cube and scaled up and out.
2./ Selected a side face and extruded out just a bit (so the extrude will be tall and thin viewed from side - but square when viewed at top
3./ Selected another face of the (just extruded) shape - and extruded that into another wall
4./ and just carried on like that...

Another thing I have been doing but am unsure if it is correct is to ...

1./ Select a poly cube and scale.
2./ Select face
3./ Select extrude
4./ Scale the shaded area, to required size
5./ Extrude it out to wherever....



Regards and many thanks Scraggy